/* vi: set expandtab sw=4 sts=4: */
/* xsystem.c - system(3) with error messages

   Carl D. Worth

   Copyright (C) 2001 University of Southern California

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.
*/

#include "config.h"

#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include "opkg_message.h"
#include "xsystem.h"

/* Like system(3), but with error messages printed if the fork fails
   or if the child process dies due to an uncaught signal. Also, the
   return value is a bit simpler:

   -1 if there was any problem
   Otherwise, the 8-bit return value of the program ala WEXITSTATUS
   as defined in <sys/wait.h>.
*/
int xsystem(const char *argv[])
{
    int status;
    pid_t pid;
    int r;

    pid = vfork();

    switch (pid) {
    case -1:
        opkg_perror(ERROR, "%s: vfork", argv[0]);
        return -1;
    case 0:
        /* child */
        execvp(argv[0], (char *const *)argv);
        _exit(-1);
    default:
        /* parent */
        break;
    }

    r = waitpid(pid, &status, 0);
    if (r == -1) {
        opkg_perror(ERROR, "%s: waitpid", argv[0]);
        return -1;
    }

    if (WIFSIGNALED(status)) {
        opkg_msg(ERROR, "%s: Child killed by signal %d.\n", argv[0],
                 WTERMSIG(status));
        return -1;
    }

    if (!WIFEXITED(status)) {
        /* shouldn't happen */
        opkg_msg(ERROR,
                 "%s: Your system is broken: got status %d " "from waitpid.\n",
                 argv[0], status);
        return -1;
    }

    return WEXITSTATUS(status);
}
